1. Field of the Invention
The present invention relates to a surgical instrument having an end effector that is opened and closed and a control method thereof.
2. Description of Related Art
In the medical field, various surgical instruments are known. A surgical instrument having an end effector that is opened and closed is known as one of such surgical instruments. Since the end effector is used to grip or exclusion body tissue, it is important to appropriately control an acting force such as a gripping force or a displacing force that the end effector applies to the body tissue.
Japanese Unexamined Patent Application, First Publication No. 2010-076012 discloses a manipulator system as a surgical instrument in which a gripper as an end effector is driven with a motor. In this manipulator system, a gripping-start angle is recognized on the basis of the output of a gripping-start estimating observer. A control is performed so that the gripping force is increased after gripping is started and a desired gripping force is achieved when the opening angle of the gripper reaches the most closed angle.